Contract Source Code:
File 1 of 1 : Yangue
/*
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* .88888888o. "Yb.
* .d888P""Y8888b "b.
* o88888 88888) "b
* d888888b..d8888P 'b
* 88888888888888" 8
* (88DWB8888888P 8)
* 8888888888P 8
* Y88888888P ee .P
* Y888888( 8888 oP
* "Y88888b "" oP"
* "Y8888o._ _.oP"
* `""Y888bood888P""'
*
* YANG V2
*
* yangue.me
*
*/
pragma solidity 0.4.24;
contract Ownable {
address owner;
constructor() public {
owner = msg.sender;
}
modifier onlyOwner() {
require(msg.sender == owner);
_;
}
}
contract Initializable {
/**
* @dev Indicates that the contract has been initialized.
*/
bool private initialized;
/**
* @dev Indicates that the contract is in the process of being initialized.
*/
bool private initializing;
/**
* @dev Modifier to use in the initializer function of a contract.
*/
modifier initializer() {
require(initializing || isConstructor() || !initialized, "Contract instance has already been initialized");
bool isTopLevelCall = !initializing;
if (isTopLevelCall) {
initializing = true;
initialized = true;
}
_;
if (isTopLevelCall) {
initializing = false;
}
}
/// @dev Returns true if and only if the function is running in the constructor
function isConstructor() private view returns (bool) {
// extcodesize checks the size of the code stored in an address, and
// address returns the current address. Since the code is still not
// deployed when running a constructor, any checks on its code size will
// yield zero, making it an effective way to detect if a contract is
// under construction or not.
uint256 cs;
assembly { cs := extcodesize(address) }
return cs == 0;
}
// Reserved storage space to allow for layout changes in the future.
uint256[50] private ______gap;
}
/**
* @title ERC20 interface
* @dev see https://github.com/ethereum/EIPs/issues/20
*/
interface IERC20 {
function totalSupply() external view returns (uint256);
function balanceOf(address who) external view returns (uint256);
function allowance(address owner, address spender)
external view returns (uint256);
function transfer(address to, uint256 value) external returns (bool);
function approve(address spender, uint256 value)
external returns (bool);
function transferFrom(address from, address to, uint256 value)
external returns (bool);
event Transfer(
address indexed from,
address indexed to,
uint256 value
);
event Approval(
address indexed owner,
address indexed spender,
uint256 value
);
}
// File: openzeppelin-eth/contracts/token/ERC20/ERC20Detailed.sol
/**
* @title ERC20Detailed token
* @dev The decimals are only for visualization purposes.
* All the operations are done using the smallest and indivisible token unit,
* just as on Ethereum all the operations are done in wei.
*/
contract ERC20Detailed is Initializable, IERC20 {
string private _name;
string private _symbol;
uint8 private _decimals;
function initialize(string name, string symbol, uint8 decimals) public initializer {
_name = name;
_symbol = symbol;
_decimals = decimals;
}
/**
* @return the name of the token.
*/
function name() public view returns(string) {
return _name;
}
/**
* @return the symbol of the token.
*/
function symbol() public view returns(string) {
return _symbol;
}
/**
* @return the number of decimals of the token.
*/
function decimals() public view returns(uint8) {
return _decimals;
}
uint256[50] private ______gap;
}
contract Yangue is ERC20Detailed, Ownable {
using SafeMathInt for int256;
using UInt256Lib for uint256;
using SafeMath for uint256;
uint256 constant public zero = uint256(0);
uint256 private constant MAX_SUPPLY = ~uint128(0);
uint256 public constant MAX_UINT256 = ~uint256(0);
uint256 public constant INITIAL_FRAGMENTS_SUPPLY = 6 * (10**4) * (10**DECIMALS);
// TOTAL_GONS is a multiple of INITIAL_FRAGMENTS_SUPPLY so that _gonsPerFragment is an integer.
// Use the highest value that fits in a uint256 for max granularity.
uint256 public constant TOTAL_GONS = MAX_UINT256 - (MAX_UINT256 % INITIAL_FRAGMENTS_SUPPLY);
uint256 public constant MAG = 10 ** 18;
uint256 public rateOfChange = MAG;
uint256 constant public DECIMALS = 18;
uint256 public _totalSupply;
uint256 public _gonsPerFragment;
mapping(address => uint256) public _gonBalances;
// This is denominated in Fragments, because the gons-fragments conversion might change before
// it's fully paid.
mapping (address => mapping (address => uint256)) public _allowedFragments;
event Transfer(address indexed from, address indexed to, uint256 tokens);
event Approval(address indexed owner, address indexed spender, uint256 tokens);
constructor() public {
ERC20Detailed.initialize("Yangue v2", "YANG", uint8(DECIMALS));
_totalSupply = INITIAL_FRAGMENTS_SUPPLY;
_gonBalances[owner] = TOTAL_GONS;
_gonsPerFragment = TOTAL_GONS.div(_totalSupply);
}
/**
* @return The total number of fragments.
*/
function totalSupply()
public
view
returns (uint256)
{
return _totalSupply;
}
/**
* @param who The address to query.
* @return The balance of the specified address.
*/
function balanceOf(address who)
public
view
returns (uint256)
{
return _gonBalances[who].div(_gonsPerFragment);
}
function computeSupplyDelta(uint256 rate, uint256 targetRate)
private
view
returns (int256)
{
// supplyDelta = totalSupply * (rate - targetRate) / targetRate
int256 targetRateSigned = targetRate.toInt256Safe();
return totalSupply().toInt256Safe()
.mul(rate.toInt256Safe().sub(targetRateSigned))
.div(targetRateSigned);
}
//two rebase functions deffo work just need to integrate them in the transfers, do this tomorrow then deploy on uniswap
function rebasePlus(uint256 _amount) private {
uint256 proportion_ = (((_amount.div(10)).mul(MAG))).div(_totalSupply);
proportion_ = MAG.add(proportion_);
int256 supplyDelta = computeSupplyDelta(proportion_, MAG);
if (supplyDelta < 0) {
_totalSupply = _totalSupply.sub(uint256(supplyDelta.abs()));
} else {
_totalSupply = _totalSupply.add(uint256(supplyDelta));
}
_gonsPerFragment = TOTAL_GONS.div(_totalSupply);
}
function rebaseMinus(uint256 _amount) private {
uint256 proportion_ = (((_amount.div(10)).mul(MAG))).div(_totalSupply);
proportion_ = MAG.sub(proportion_);
int256 supplyDelta = computeSupplyDelta(proportion_, MAG);
if (supplyDelta < 0) {
_totalSupply = _totalSupply.sub(uint256(supplyDelta.abs()));
} else {
_totalSupply = _totalSupply.add(uint256(supplyDelta));
}
if (_totalSupply > MAX_SUPPLY) {
_totalSupply = MAX_SUPPLY;
}
_gonsPerFragment = TOTAL_GONS.div(_totalSupply);
}
/**
* @dev Transfer tokens to a specified address.
* @param to The address to transfer to.
* @param value The amount to be transferred.
* @return True on success, false otherwise.
*/
function transfer(address to, uint256 value)
public
returns (bool)
{
bool isNewUser = balanceOf(to) == zero;
uint256 gonValue = value.mul(_gonsPerFragment);
_gonBalances[msg.sender] = _gonBalances[msg.sender].sub(gonValue);
_gonBalances[to] = _gonBalances[to].add(gonValue);
if(isNewUser && balanceOf(msg.sender) > zero) {
rebasePlus(value);
} else if( balanceOf(msg.sender) == zero) {
rebaseMinus(value);
}
emit Transfer(msg.sender, to, value);
return true;
}
/**
* @dev Function to check the amount of tokens that an owner has allowed to a spender.
* @param owner_ The address which owns the funds.
* @param spender The address which will spend the funds.
* @return The number of tokens still available for the spender.
*/
function allowance(address owner_, address spender)
public
view
returns (uint256)
{
return _allowedFragments[owner_][spender];
}
/**
* @dev Transfer tokens from one address to another.
* @param from The address you want to send tokens from.
* @param to The address you want to transfer to.
* @param value The amount of tokens to be transferred.
*/
function transferFrom(address from, address to, uint256 value)
public
returns (bool)
{
bool isNewUser = balanceOf(to) == zero;
_allowedFragments[from][msg.sender] = _allowedFragments[from][msg.sender].sub(value);
uint256 gonValue = value.mul(_gonsPerFragment);
_gonBalances[from] = _gonBalances[from].sub(gonValue);
_gonBalances[to] = _gonBalances[to].add(gonValue);
if(isNewUser && balanceOf(from) > zero) {
rebasePlus(value);
} else if(balanceOf(from) == zero) {
rebaseMinus(value);
}
emit Transfer(from, to, value);
return true;
}
/**
* @dev Approve the passed address to spend the specified amount of tokens on behalf of
* msg.sender. This method is included for ERC20 compatibility.
* increaseAllowance and decreaseAllowance should be used instead.
* Changing an allowance with this method brings the risk that someone may transfer both
* the old and the new allowance - if they are both greater than zero - if a transfer
* transaction is mined before the later approve() call is mined.
*
* @param spender The address which will spend the funds.
* @param value The amount of tokens to be spent.
*/
function approve(address spender, uint256 value)
public
returns (bool)
{
_allowedFragments[msg.sender][spender] = value;
emit Approval(msg.sender, spender, value);
return true;
}
/**
* @dev Increase the amount of tokens that an owner has allowed to a spender.
* This method should be used instead of approve() to avoid the double approval vulnerability
* described above.
* @param spender The address which will spend the funds.
* @param addedValue The amount of tokens to increase the allowance by.
*/
function increaseAllowance(address spender, uint256 addedValue)
public
returns (bool)
{
_allowedFragments[msg.sender][spender] =
_allowedFragments[msg.sender][spender].add(addedValue);
emit Approval(msg.sender, spender, _allowedFragments[msg.sender][spender]);
return true;
}
/**
* @dev Decrease the amount of tokens that an owner has allowed to a spender.
*
* @param spender The address which will spend the funds.
* @param subtractedValue The amount of tokens to decrease the allowance by.
*/
function decreaseAllowance(address spender, uint256 subtractedValue)
public
returns (bool)
{
uint256 oldValue = _allowedFragments[msg.sender][spender];
if (subtractedValue >= oldValue) {
_allowedFragments[msg.sender][spender] = 0;
} else {
_allowedFragments[msg.sender][spender] = oldValue.sub(subtractedValue);
}
emit Approval(msg.sender, spender, _allowedFragments[msg.sender][spender]);
return true;
}
}
library SafeMath {
int256 private constant MIN_INT256 = int256(1) << 255;
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts with custom message on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
function abs(int256 a)
internal
pure
returns (int256)
{
require(a != MIN_INT256);
return a < 0 ? -a : a;
}
}
library UInt256Lib {
uint256 private constant MAX_INT256 = ~(uint256(1) << 255);
/**
* @dev Safely converts a uint256 to an int256.
*/
function toInt256Safe(uint256 a)
internal
pure
returns (int256)
{
require(a <= MAX_INT256);
return int256(a);
}
}
library SafeMathInt {
int256 private constant MIN_INT256 = int256(1) << 255;
int256 private constant MAX_INT256 = ~(int256(1) << 255);
/**
* @dev Multiplies two int256 variables and fails on overflow.
*/
function mul(int256 a, int256 b)
internal
pure
returns (int256)
{
int256 c = a * b;
// Detect overflow when multiplying MIN_INT256 with -1
require(c != MIN_INT256 || (a & MIN_INT256) != (b & MIN_INT256));
require((b == 0) || (c / b == a));
return c;
}
/**
* @dev Division of two int256 variables and fails on overflow.
*/
function div(int256 a, int256 b)
internal
pure
returns (int256)
{
// Prevent overflow when dividing MIN_INT256 by -1
require(b != -1 || a != MIN_INT256);
// Solidity already throws when dividing by 0.
return a / b;
}
/**
* @dev Subtracts two int256 variables and fails on overflow.
*/
function sub(int256 a, int256 b)
internal
pure
returns (int256)
{
int256 c = a - b;
require((b >= 0 && c <= a) || (b < 0 && c > a));
return c;
}
/**
* @dev Adds two int256 variables and fails on overflow.
*/
function add(int256 a, int256 b)
internal
pure
returns (int256)
{
int256 c = a + b;
require((b >= 0 && c >= a) || (b < 0 && c < a));
return c;
}
/**
* @dev Converts to absolute value, and fails on overflow.
*/
function abs(int256 a)
internal
pure
returns (int256)
{
require(a != MIN_INT256);
return a < 0 ? -a : a;
}
}